"Halloween" Crab ID? Land crab or aqua?

Tarantulady

New Member
"Halloween Fiddler" ID/care?

Please read through. I edited and the question changed. Wasn't sure if should do that here or a new thread, so editing here to save clutter.

Original post:
My boyfriend was at our LFS and they'd just received a mysterious shipment of tiny crabs. They'd been shipped as "strawberry crabs", which they very obviously are not. He picked one up for me. There are more of them available, and I'd like to get a group going in my 10 or 65, but we don't have an ID and the LFS is completely stumped.

He is small enough to sit squarely on a quarter (coin). The eyes make me think of fiddler crabs, but the LFS said they've been in the store for 1 week without land, no deaths. None of them had "fiddler" arms, either. His back is orange and his legs are blue (almost black) with white on them. His eyestalks are cream/off-white. Notice the two "fang" markings on the front?

He'll reside in my 10, with my arrowhead crab for the time being. If he's semi-aquatic I'd like to know, so I can set him up with something appropriate. I normally wouldn't buy mystery animals, but we've never seen anything like this and we couldn't miss out!

Photos incoming, please let me know what you guys think?

Edit: here are photos. He's still acclimating so photos are bad.


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Ok, seems they are likely an immature male and two female Fiddlers of some sort. We've moved them to a mostly-sand critter keeper with the water they acclimated to (from my ten). We were thinking of putting them in my spare ten, which was only growing extra aiptasia for my little berghia side-project. How does this sound, invert people?... A 10g with "cycled" sand, small heater, airstone. I was going to use the same water I make for my other tanks, then add a little dirty from my tanks from time to time, so they have gross stuff to eat. Any pointers would be SO welcome. Let me know if this setup sounds awful.

I don't want to return them to the LFS since I guess they would drown.
 
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PSU4ME

JoePa lives on!!!
Staff member
PREMIUM
That surely is an interesteing crab.....I can find an ID. Saw one with long white eyes like that but the rest of the body/color was off.

Interesting little bugger.
 

Oxylebius

Well-Known Member
It looks like a fiddler crab. Males have the secondary-sexual characteristics (e.g., the asymmetric claws). Females and juvenile males look similar and won't have the large claw. Based on the small size of this one, it is either a female or juvenile male.
 

Oxylebius

Well-Known Member
It may be either:
Uca coarctata
Uca tangeri
Not 100% on this ID.

Juveniles will go through a series of color changes before ending up with its adult colors, so id'ing it right now may be difficult.

Family Ocypodidae; Ghost Crabs, Fiddler Crabs. Common genera: Ocypode, Uca. Former live in moist sand, emerging at night to feed. Both have elevated eye stocks. Ghost crabs have characteristic thickened, elevated eyestalks. Both have enlarged claws. Fiddler Crab males sport an oversize claw that they use for signaling.
 
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Tarantulady

New Member
Haven't been back in a while, I know. Thanks for the replies. I got them in a half-water 10 g with rubble and they are still alive and fast runners.
 

Oxylebius

Well-Known Member
very cool! glad to hear they are still doing well.
Any updated pics of the tank and crabs?

Keeping them in the 10gallon w/half water half sand should work out well. The question of needing a heater or not, guess it depends where the crabs came from, tropical, semi-tropical, or temperate climates. Updated photos would help with a positive ID - or look through this website, clicks on 'photos' link, determine species, then look up where they are found.

I wouldn't add 'dirty' water from your other tanks, they are still sensitive to ammonia/nitrite/nitrate. Aiptasia will still sting your crabs. Not sure about the nudis, I don't see any issues there.

They are crabs, thus are scavengers and will most likely eat anything you give them - whatever you are feeding your fish should work out fine for them as well.
 

Tarantulady

New Member
Sad update: I 90% positively ID'ed them as red-claw crabs because the look changed as they grew. Unfortunately, they died at once. It was my fault because the salinity rose (I had a dry day in the house).
 
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